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62 Cards in this Set

  • Front
  • Back
How are man made fibers made
Taking an oil, boiling it and ending with a polymer
What are the 3 results of polymer synthesis
Tow, Yarn, Film
What is a tow?
A thick rope made of many more filaments than yarn (production is higher and less expensive)
What is a yarn?
Thin, various uses more expensive than a tow, spinerette has less holes
What is a film?
polymer that's extruded thru a thin slot, like plastic wrap, its often cut and made into filbrilated yarn for strings and ropes
Wet spinning (Process, fiber types, and disadvantage)
A fiber forming material is dissolved into a solvent, and extruded into a bath (that the fiber is insoluble in). Wet spinning is best for tow production, acrylic, rayon, bamboo and kevlar (least desirable because it uses a lot of chemicals)
Dry Spinning (Solvent Spinning) (Process, fiber types, and disadvantage)
Polymer is mixed with a volatile solvent, then pushed extruded and blasted with hot air. Used for acrylic, acetate, and thermoplastic fibers. Major disadvantage: Volatile substances are nasty and need to be recycled.
Melt Spinning (Process, fiber types, and how to make economical)
A thermoplastic polymer is melted and pushed thru the spinnerette and then cooled down. Polyester, nylon, polypropylene, polyethylene. Using polymer with low melting point makes it more economical
What is a fiber?
1 thing or entity. Textile raw material, characterized by flexibility, fineness, and high ratio of length to thickness
Filament
A fiber of indefinite length, (most people say its over 10 ft long)
Staple Fiber
Fibers of short length (typically under 12 inches)
Monofilament
1 single filament (ie, fishing line)
Multifilament
Yarn consisting of more than one filament
Tow
An assembly of a large number of filaments (thick)
Tex
The mass in grams of 1 km of a material
Decitex
The mass in decigrams of one km of material
Denier
The mass in grams of 9000 m of a filament or yarn
What does 17dtex f1 mean?
A single filament with a count of 17 decitex
What does 133dtex f40t0 mean?
A multifilament (40 filaments) with zero twist with a count of 133 decitex
What does 133 dtex f40S1000; R136 dtex mean?
A twisted multifilament (40 filaments), 133 dtex count, 1000 turns per meter, with a Resultant count of 136 dtex
What does R69.3 tex Z400/2S600
2 ply yarn with 69.3 tex resultant count, that has 400 turns z twist, and made with 2 yarns with 600 turns S twist each
What does R123 tex Z200/3S400/2Z700 mean?
A cabled yarn, with a resultant count of 123 tex. made with 200 turns Z twist thats made up of 3 yarns with 400 turns S twist, and 2 yarns with 700 turns Z twist
What does 20 tex Z700x2S400x3Z200
A 20 tex yarn, with 700 turns z twist, take 2 yarns with 400 turns S twist with 3 yarns with 200 turns Z twist
What effect does fiber fineness have on fiber properties
Stronger fabrics, better hand, increase surface area, higher abrasion, more absorbant
What effect does Tenacity have on fiber properties
Improved abrasion, performance and processibility, but as tenacity increases, elongation decreases
What effect does cross section have on fiber properties
Affects how fibers pack together, fibers with round cross-sections reflect light (shiny)
What effect does chemical reactivity have on fiber properties
Affects how fibers dye
What is thermoplastic behavior?
When you can heat and weight the fiber, then cool it and it stays the same stretched length (stays elongated). Plastic fibers have a low recovery
Fibers with a high strength have a low what?
Extension
Tg
Glass Transition Temperature: when a glass or polymer becomes brittle upon cooling or soft when heated
What are 6 uses of filament yarns?
Apparel, Home Furnishings, Automotive, Industrial, Sports, Medical
What apparel applications are filaments used in?
hosiery, menswear, womenswear, intimate apparel
What home furnishing and automotive applications are filaments used in?
upholstery, carpets
What industrial applications are filaments used in?
tires, drive belts, sewing threads, ropes, lifting harnesses, nets
What sport applications are filaments used in?
sailcloths, fishing line, tennis racquets, sports clothing, composites bows, golf clubs, fishing rods
What medical applications are filaments used in?
internal (artificial arteries, ligaments, etc), external (support hose, dressings), sutures, dental floss (most widely used medical textile)
What military applications are filaments used in?
composites, uniforms, protective clothing, parachutes, braids and ribbons
What is winding?
the transfer of yarns from spinning tubes onto packages more suitable for weaving, knitting, twisting. The take up of yarn from an extrusion, texturing, or other processing machine. THE TRANSFER OF YARN FROM ANY PACKAGE TO ANOTHER. AND TAKE UP FROM SPINNING, EXTRUSION AND TEXTURIZING
What are the objectives of winding?
To create a large fault free package that is suitable for further processing, the yarn should readily unwind from the package at the next process (this is different for different packages).
Additional objectives of winding
Lubricate yarns if necessary, introduce a minimum number of joins, acheive high productivity, create a package with a maximum amount of yarn (within geometrical constraints), create a stable package that will easily unwind when required
Problems in winding
Defects like thin places, thick places, neps and hairiness because of the high speed of winding and the yarn being dragged through the air and over mechanical parts
The best package
A package made up of yarn from 20 bobbins that would have only 20 joins (at minimum)
What are the two types of winding packages?
cheese and cone
What is a cheese package?
A package that is even on all sides like a rectangle. Its easier to produce and is good for yarn dyed packages. used for dyeing and weaving
What is a cone package?
Package thats angled in at the top and bottom. Its more difficult to wind and maintain tension control, but its easier to unwind, its usually used for knitting
What is an in-between or fits all package?
A cheese with a slight angle. This is acceptable for weaving, knitting and dyeing
Balloon controller
Keeps yarn from ballooning during takeoff
What is most necessary for proper winding and unwinding
Tension control
Split drum winder
It drums forward and backwards, traverse is built into drive mechanism, its cheap and efficient and has the same winding speed
Patterning
Pronounced bands where yarns traverses when winding, can be prevented with an antipatterning device
How does an antipatterning device work?
It slows package down and moves up or rocks package to prevent patterning
What causes a rounded end on a package?
Too much compression pushes out top of package (the rounded part is loose yarns that will tangle and break) (more common with elastic yarns)
Why is it important for a package to look good?
Because people won't buy it if it looks ugly because it indicates that the yarn is bad
Clearing
Removing defects from the yarn during winding
What should be kept in mind when clearing?
The fault must be worse than the join needed to fix it, not all defects can be eliminated, so the clearer must be set to only remove those that will cause problems in later processing (set machine so it only removes certain faults)
Splicing
Joining the two ends by weaving their strands together
What should be kept in mind when splicing?
the splice/knot created needs to be smaller than the defect being removed
How are yarns spliced?
Untwist the ends and rejoin/twist them back together by using a mechanical twisting device, (some still use glue)
Waxing
wax is applied to modify yarn friction, the right wax should be chosen according to end use. Typically 1.5 grams is used per kg of yarn (.15% pickup)
Doffing
Wind a predetermined size, weight, etc, then its automatically replaced with a new empty package. Most machines are equipped with automatic doffing, because the less hands on a package the better
Feeding to winders can be done in 3 ways
manually, semi-automatically, automatically (done by using a link between spinning frame and winder)
Link winding
Winders are equipped with splicing and yarn monitoring units, and spinning packages can be tracked in order to determine which spindles are producing defective yarns (have to match spinning frame rate to winding frame rate)